Linus Says Pre-2.6 is Coming

gomoX writes "As seen on C|Net , Linus has announced that the pre-2.6 series will be starting in early July. Despite not having been able to meet the release goal for 2.6 in June 2003, the next stable version is not as far away as you may think. You can take your guess based on the fact there was a 9 month period between first test version of 2.4 and the official release of 2.4.0 on January 2001."

I'm posting this on top of 2.5.74

[Genyin]

In fact, 2.5 isn't that bad right now... certainly, it would be crazy to use it on a production system unless you really know what you're doing[1], but it's quite usable, and the scheduling has really improved.

[1] in which case you probably wouldn't use it on said production system... ;)

probably, yeah.

[pb]

Even the regular Gentoo kernel has a lot of extra patches in it [purdue.edu], including the O(1) Scheduler, and Low-latency scheduling; works great for me.

Re:What have I got to look forward to?

[bethane]

Being a LKML lurker, here are a few of the new features.

In-kernel Module Loader and Unified parameter support: http://www.kernel.org/pub/linux/kernel/people/rust y/patches/Module/

Nanosecond Time Patch: http://www.ussg.iu.edu/hypermail/linux/kernel/0210 .3/0793.html

Fbdev Rewrite: http://www.uwsg.iu.edu/hypermail/linux/kernel/0111 .3/1267.html

Linux Trace Trollkit (LTT): http://www.uwsg.iu.edu/hypermail/linux/kernel/0204 .1/0832.html

statfs64: http://marc.theaimsgroup.com/?l=linux-kernel&m=103 610918825614&w=2

POSIX Timer API: http://marc.theaimsgroup.com/?l=linux-kernel&m=103 553654329827&w=2

Shared Pagetable support: http://marc.theaimsgroup.com/?l=linux-kernel&m=103 498293902006&w=2

Hotplug CPU Removal Support and Kernel Probes

2.5.x

[bazik]

I am using a rock solid 2.5.70 since its released and its performs just great! And having Morton and Torvalds at OSDL is a good thing (tm) :)

Alan Cox on kernel 2.6

[k-hell]

KernelTrap is running a story [kerneltrap.org] on an interview Alan Cox gave at LinuxUser & Developer Expo 2003 [linux-expo.co.uk] in Birmingham, U.K. A summary [linux-expo.co.uk] of Alan's talk is also available.

Re:What have I got to look forward to?

[anshil]

I think for me most important the ALSA sound system is finally part of the linus kernel. Meaning you do not need to patch the kernel anymore to get recent sound support.

Re:Distro Upgrade?

[Vanieter]

I would tend to say you'd need to modify your apps so that they'll run correctly with the new ALSA interface for sound support - although it supports OSS/lite emulation pretty much perfectly (as far as I know of)

Also, modules names have (I think) changed, so a change in the init scripts would probably be useful. It depends on your distro though - I'd say distros like Slackware and Debian will have guides or automated tools for migration. Commercial distributions will probably have to release a new version (RedHat 10 ? Gods).

Although maybe I'm wrong, I never managed to get a working 2.5.x kernel on my Debian box =)

Re:Microsoft leads the way with SP4 for Windows 20

[be-fan]

The Windows kernel hasn't changed significantly since the NT4 -> Win2K change. The biggest improvement in the XP kernel was pre-faulting the pages of large processes. Meanwhile, in 2.6, the block I/O layer, VM layer, scheduler, and sound system are brand new. And the whole kernel was made preemptible! Shortly after 2.6, ReiserFS 4 (which looks very promising from initial benchmarks) will be released. In all, 2.4 -> 2.6 will be like NT4 -> XP!

PS> Before anyone bitches about rewrites being a bad thing, look at things this way. Such extensive changes are necessary for the continually growing range of systems Linux is expected to run on. 2.0 and 2.2 were greatfor single CPU servers, or SMP machines with only a few processors. 2.4 is very usable for heavy-duty machines with many more processors. 2.6 (along with the changes that help interactivity) will make an excellent kernel for desktop machines and workstations. In 2.8, the focus will be on optimizing the core algorithms to run on large-scale NUMA machines.

Re:Distro Upgrade?

[Genyin]

Also, the old OSS modules are still in the kernel. I haven't tried them in 2.5, and they are marked with a big DEPRECATED, but they're still there.

Note, of course, as I've said elsewhere, you do need the new module-init-tools [kernel.org]; I'd imagine that would be the most likey reason you'd have trouble getting a 2.5 kernel working, followed closely by an out of date/broken driver.

Re:What have I got to look forward to?

[bartc]

Here's a nice overview by Guillaume Boissiere:

http://www.kernelnewbies.org/status/latest.html [kernelnewbies.org]

And a document by Dave Jones:

http://www.codemonkey.org.uk/post-halloween-2.5.tx t [codemonkey.org.uk]

Re:Should I get excited over any of these features

[xenocide2]

Well, the nanosecond patch is critical for make on fast computers, since it uses filesystem timestamps. If you're running gentoo on a brand new desktop it might be a good idea.

The fbdev patch reduces the size of the framebuffer, so if you like framebuffered consoles, it will reduce your kernel size.

If you have multiple processors, the Shared page table patch will help reduce page table sizes, and thereby improve performance, marginally. More RAM = more file cache / less disk paging; shared data -> higher cache coherency = faster kernel performance in memory mapping.

Additionally there seems to have been some mucking around with tweaking the adaptive scheduler so X gets more time when it needs it. The performance metrics have been kind of squishy, but the general consensus is that X and related 'interactive' processes are more responsive.

Re:Oh yeah? Well, I'm on 2.5.75, buddy!

[Alan]

I played around a bit with .71-.73, but the big thing that got me was that my mouse speed in gnome was sped up by about 10x over 2.4. I had to set the accel down to the lowest setting in gnome to make it usable, compared to about the 25-50% setting with 2.4. Of course, there is no similar setting for GDM.

I'm guessing this is due to the new keyboard/mouse modules, but who knows. Hopefully this is one of the things that will get shaken out when 2.5 and 2.6 become more mainstream and the KDE/GNOME folks set things up to work nicer with the devel kernels.

Re:What have I got to look forward to?

[alienw]

You never had to patch the Linux kernel to get ALSA. It could easily be compiled separately.

Re: more salient features

[Anonymous Coward]

Don't forget merger of larger projects into the kernel, namely:

CryptoAPI
IPsec
ALSA
XFS

No more patching the kernel/building module packages for those features!

Also, improved latency with (O)1 Scheduler and other I/O performance tweaks will be native to the kernel.

Re:Question about 2.6 adoption by distros/maturity

[XO]

2.4 actually had some fairly serious flaws in the middle of it, but the modifications that were done that caused those flaws were, imho, necessary for further evolution.

Certainly pre-2.6 should squash out most bugs, however !! remember the vast majority of Linux users out there are NOT likely playing with 2.5.x or will be with pre-2.6!

The stress tests that come from 2.6.0 being announced and suddenly being unleashed upon tens of thousands more users (or hundreds of thousands more machines) than 2.5.x is will shake out all remaining serious flaws.

Re:What the heck?!

[aetherspoon]

Basically, Slashdot has a story comment system that sorta resembles boards as well as a story submission system that sorta resembles a moderated topic list.

It isn't a messageboard site though.

stability

[Anonymous Coward]

(of course, a beta version of Linux is probably more stable than a release version of Windows

I'm posting this anonymously because I'd be ashamed to have my name tied to defending Windows. Your comment is definitely true for versions of Windows up through ME. But I've been running XP on a Sony Vaio for the past fourteen months, and I have never had to reboot. In fact, I don't even know if XP has a blue screen of death, cuz if it does I've sure never seen it. Despite its thousand liabilities and the fact that Windows helps fund a scummy corporation, I don't think that XP can be criticized for instability.

Re:I'm posting this on top of 2.5.74

[tuba_dude]

I've been using the various revisions of the 2.5 series for a few months now. You would not believe how much more responsive X is. Well, you might, but that's not the point. ;) It's been great, disk i/o is a bit faster, and the only problems I've had were with binary-only drivers.

Re:What has happened to Slashdot?

[Anonymous Coward]

preeminent or pre-eminent ( P ) Pronunciation Key (pr-m-nnt) adj. Superior to or notable above all others; outstanding.

Not gonna comment on parent poster's spelling skills, but you, sir, are in dire need of a dictionary.

Re:load kernel from kernel?

[djcapelis]

I think it's probably refferring to the User mode Linux patch perhaps? Which allows one kernel to act as a parent for another to allow a sandbox to run a kernel in. Helps with debugging and telling someone you're giving them a dedicated server when you have six kernel instances running on the same box.

Re:Reiserfs

[Anonymous Coward]

No, since Reiser4 hasn't even been released yet, AFAIK, and even when it has, it will require a lot of testing. Reiser4 was one of the things I was looking forward to most in 2.6, so that I could install Gentoo with it, and now I'm going to have to wait much longer since there is no reasonable way to patch the kernel while installing Gentoo and because Reiser4 will not be included in the stable kernel due to significant changes to VFS code.

xset!

[bahamat]

Does nobody even know how their system works anymore? xset people! xset!!

Re:Question about 2.6 adoption by distros/maturity

[iabervon]

First of all, there are going to be a lot of kernels which start 2.6 before 2.6.0, due to the whole stabilization process. Secondly, I think that distros will have a more substantial role in testing the kernels than they have in the past, relative to individual users, so the big stress tests will come when IBM, Red Hat, and Oracle pick up 2.6-pre1 to test; in the past, the big stress tests came when 2.4.0 got a lot of end users to start testing. Third, Andrew Morton is intending to be a release engineer, which Linus has done badly in the past (that not being what his style is good for), which will mean that 2.6.0 will be carefully tested, unlike previous .0 versions.

Of course, this is due to evolution is the process of releasing stable series kernels, not evolution in the kernel code itself; through the middle of 2.5, everything got broken, and has now mostly been fixed.

Re:Oh yeah? Well, I'm on 2.5.75, buddy!

[Anonymous Coward]

From what I heard, Linus Torvalds himself didn't initialy enjoy the patch submission of another developer which caused prioritization improvments to X server and Input Devices (Keyboard, Mouse). You are talking about that patch. To my remembrance, Linus said, somewhere along the lines of, "Windows NT did this...bad...verry bad...We are supposed to entreat all applications/devices equaly, not priority in such of others...bend over, Ralph#~Jim#~Miguel, I'm spanking you today...ok, you can have the patch included. No hard feelings?"

This improvment you speak of is some sort of modification to allow automatic renice(1). In the past, using a Dual Pentium Pro UltraWide SCSI graphics workstation, I had a problem with keyboard and mouse keys becoming stuck in the software state as well as audio playback skipping. Perhaps this patch is what makes the lame determination upon what peice of software needs priority over other software; that still doesn't help the system dig itself out of a whole when every peice of software wants highest priority or whatnot. This code, honestly, is a Bad Thing(TM) != Good Thing(TM).

(1)renice, give priority to applications. System level application "nice" with numerical parameter and string parameter; -20 being lowest priority, 0 being normal priority, +20 being highest priority; followed by the name of the daemon or thread or application that will have its priority changed.

Re:Should I get excited over any of these features

[Anonymous Coward]

Umm, no the nanosecond patch is not critical for make on fast computers. Sometimes a file might get rebuild when it shouldn't. Thats all.

Shared page tables are not in 2.5, nor are they likely to be in 2.6. It has nothing to do with multiple CPU machines.

Re:Uh, question.

[stor]

Well not obsolete it but people may be interested in the new bridging firewall code, ebtables [sourceforge.net]

And yes I got the joke...

Cheers
Stor

Re:devfsd and lvm

[Pegasus]

I don't know if devfs is gone yet, but it's gonna be replaced by sysfs sooner or later. Lvm on the other hand is gone, replaced by device mapper, on which both lvm2 and evms2 are built. Evms2 looks extremely well for a nice gui volume management.